Distributor gauge



July 7, 1959 E. TOOKE 3,132

DISTRIBUTOR GAUGE Filed Aug. 13, 1957 nited States Patent 7 2,893,132DISTRIBUTOR GAUGE Ernest Toolre, London, England Application August 13,1957, Serial No. 677,991 4 Claims. (Cl. 33180) This invention relatestoa method of and means for setting the contact points of thedistributor of an internal combustion engine. The usual method employedfor setting the gap between the contact points of a distributor consistsin slowly turning the engine over until a lobe on the dam of thedistributor engages the heel of a spring loaded pivoted contact breakerand the gaps between the contact points of the distributor are fullyopen whereupon the necessary adjustment is eifected to 1ncrease ordecrease the gap. With internal-combustion engines provided with astarting handle it is a simple matter to turn the engine over until thelobe of the cam and the heel of the contact breaker are in the requisiteposition, but with certain present day motor-cars a starting handle isnot always available and it then becomes necessary to move the car,whilst in gear, to-or-fro until the heel of the contact breaker and lobeengages at a point where the contact points are held fully open. Theobject or the present invention is to provide a method of setting oradjusting contact points of a distributor which can be more quickly andeffectively conducted than hitherto and at the same time will avoid thedisadvantage where lack of a starting handle renders the operationdifficult.

According to the invention a method of setting the contact points of adistributor consists in freeing the fixed contact support plate,shrouding the cam of the distributor with a cylindrical sleeve,introducing a limit gauge of a predetermined thickness between thecontact of the breaker arm and the relatively fixed contact of thedistributor, closing the contacts on the limit guage, re-secur' ing thecontact breaker support plate and finally, removing the sleeve and limitguage.

Preferably, the wall thickness of the sleeve and the limit gauge areco-releated to give the correct gap between the contact points afteradjustment and their removal.

The invention also includes means for setting the contact points of thedistributor of an internal combustion engine comprising in combination acylindrical sleeve having a predetermined wall thickness and a limitguage also of a predetermined thickness, the two dimensions beingrelated to give the required gap between the contact points of thedistributor after setting by the means described. The sleeve and limitguage are preferably anchored together by, for example, a short lengthof chain. I

It will be appreciated that it is essential that there should bereasonably close fit between the sleeve and the cam, and that apparentplay should not be present. It has been discovered, however, that camsfor various types of distributors differ slightly in their overalldimensions and furthermore, wear, in the course of time, will effectsuch dimensions, the variation in the diameter of the different cams mayvary as much as .006 of an inch. Accordingly, it is preferred that thesleeve should have a spring character whereby resilience is impartedthereto so that as a result cams of differing dimensions withincomparatively narrow limits cam be shrouded for the 2,893,132 PatentedJuly 7, I959 2 purpose specified. To this end the sleeve is slitlengthwise and conveniently produced from hardened and tempered stripsteel, one edge of. which may be quarter rounded to form a grip.

Alternatively, the entry end of this sleeve is slit to approximatelyhalf its length, the slit extending from the entry end of the sleeve andterminating in an arcuate slit extending partly around the circumferenceof 'the sleeve. The slit can be of T-or-L form in elevation and providesa double flap of spring character to the lower part of the sleeve in thefirst instant and a single spring flap in the second instant.

The invention also is directed to a method of producing a sleeveaccording to the foregoing paragraph, consisting in rolling a length ofstrip spring steel, one edge of which may be beaded or radiused, into alongitudinal- 1y slit sleeve, subsequently hardened and tempered.

The device according to the invention will hereinafter be referred to asan ignition gauge.

In order that the invention may be clearly understood and readilycarried into effect, reference is directed to the accompanying drawing,wherein:

Figure 1 shows in side elevation an ignition gauge according to theinvention. 7

Figure 2 is a section on the line IIII of Figure 1.

Figure 3 is a side elevation of a modified form of sleeve. V I

Figure 4 shows in side elevation a modified form of ignition gaugeaccording to the invention.

Figure 5 is a section on the line V-V of Figure 4, and

Figure 6 shows in elevation a simplified form of sleeve.

Referring to the drawing in general, the ignition gauge consists of ashort length of metal tube constituting the sleeve a of the invention,conveniently with a highly polished internal and external surface of adefinite wall thickness, for example, 0.25 of an inch, and a limit gaugeb connected to the sleeve by a chain c. As shown in Figures 1, 2 and 3,one end of the sleeve a is circumferentially beaded as at d to form aconvenient means of gripping the sleeve when being placed over the camof a distributor, the internal dimensions of the sleeve being such as tofrictionally engage the cam. The limit guage b used in conjunction withthe sleeve comprises a slip of metal of the desired thickness, i.e.,.043 of an inch and suitably shaped for manipulation.

It will be appreciated that the sleeve need not have a predeterminedwall thickness but in order to ensure the correct gap between thecontacts of the distributor the limit gauge must have a thicknessequivalent to the wall thickness of the sleeve, the dimensions of thedesired gap, plus an additional wall dimension to neutralize the angularmovement of the contact breaker arm when the sleeve is placed inposition. For example, to obtain a gap of 0.0015 21 gauge of 0.0046 isneeded with a sleeve thickness of 0.0025.

In order to impart additional resilience to the sleeve so that cams ofrelatively differing dimensions, with narrow limits, may be shrouded,the entry end of the sleeve a is slit lengthwise for a part of itslength or provided with an L-shaped slit e as shown in Figure 1, or a T-shaped slit 7 as shown in Fig. 3. Alternatively, the sleeve a may have alongitudinal slit g from top to bottom as shown in Figures 4 and 5 or 6,for the same purpose.

Figures 4 and 5 illustrate a construction in which the sleeve isprovided with an outwardly turned upper edge h to facilitate its use.The sleeve a shown in Figures 4 and 6 is conveniently manufactured byrolling into shape from strip spring steel of the requisite dimension,being subsequently hardened and tempered.

In use the fixed contact plate of the distributor is made free from itsbase support by loosening its fixing screws and the sleeve slipped overthe cam of the distributor with the heel of the contact breakerabutting. The limit gauge is introduced between the two contact pointswhich are closed thereon and the contact breaker support platere-secured. Removal of the sleeve and the limit gauge will leave thecontact points correctly set.

The spring means provided in the construction of the sleeve enables thelatter to be held'resiliently to the cam and closely engaged therewith,it being understood that the sleeve in addition to being usable forstandard size cams can also be fitted to over or undersize cams withincertain limits. 7 i It will be appreciated that the invention is capableof use for multi-cylinder engines. and although the sleeve and limitgauge are preferably made of metal, nonmetallic substances may be usedfor their manufacture, such as one of the plastics, andfurther, a numberof single longitudinal slits may be formed in the sleeve or theT'-or-L-shaped slits may be duplicated at opposite sides of the sleeve,or alternatively, the sleeve may be quite plain and unslitted.

What I claim and desire to secure by Letters Patent is:

1. An ignition gauge for adjusting the setting of the contact points ofthe distributor of an internal combustion engine having a .breaker camand follower comprising, in combination, a cylindrical sleeve having awall of uniform. thickness for supported engagement upon the breaker camof the distributor adjacent to the follower of the breaker unit, saidwall having opposite end edges ment of a breaker cam and follower,comprising a cylindrical sleeve having a flexible side wall ofsubstantially uniform thickness for slidable engagement upon the breakercam of the distributor to be adjusted, said side wall havinglongitudinally spaced apart terminal edges, portions of said side walldefining a slit communicating with one of said terminal edges andextending partially toward the opposite terminal edge of said side wall,the outside diameter of said one edge of said side wall being adjustableto conform substantially to the sides of a circle circumscribed by thebreaker points of the breaker cam, and said opposite terminal edge ofsaid side wall being of substantially constant diameter frictionallyreceiving the breaker cam longitudinally therewithin removably to securesaid sleeve upon the breaker cam.

3. An ignition gauge for adjusting the setting of the distributorcontact points as set forth in claim 2 wherein said slit is ofsubstantially L-shaped configuration having one leg extendingperpendicularly inwardly from said one terminal edge of said wall, and aperpendicularly related leg of said L-shaped slit extending parallel toand spaced inwardly from said opposite terminal edge of said side wall.

4. An ignition gauge for adjusting the setting of the distributorcontact points as set forth in claim 2, wherein said slit is ofsubstantially T-shaped configuration having one base leg extendingperpendicularly inwardly from said one terminal edge of said side wall,anda perpendicularly related cross leg of said T-shaped slit extendingparallel to and being spaced inwardly from said opposite terminal edgeof each side wall.

References Cited in the file of this patent UNITED STATES PATENTS1,435,887 Anderson Nov. 14, 1922 1,545,458 Pearson July 7, 19252,453,774 Basista Nov. 16, 1948 2,838,842 Hassler June 17, 1958

